This document outlines the evolution of HTML from its earliest use in 1988 to HTML 5.1 in 2016. It lists the major versions and drafts of HTML released over this period, including HTML 2.0, HTML 3.2, HTML 4.01, XHTML 1.0-1.1, HTML 5.0, and HTML 5.1. The timeline shows the increasing standardization and capabilities of HTML through the years.